SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9bf0a00f43851a9003faf1d703b5332d0e82e96d2705260b05d23b282f994e1' 
  AND token = 'eh0mANDaktEH9lAZkHEVqUJ8Xec0v7Um3zZKFelPVAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}